Sour crop that won't go away

My 5 month old pullet has had crop issues since she was a month old. I have tried expelling her crop, taking away her food, yogurt and ACV to red wine. I purchased a crop bra that seems to work but she keeps getting her feet caught in it. When I remove it, her crop get huge again. Please give me any advise that would help her. I hate to see her live a life like this and I really don't won't to put her down. She has developed and weights the same as her sisters. Please help me. I feel desperate!

The fastest way would be to take away the layer and give her straight single ingredients. Start with just corn since that is the greatest part of the layer. If things improve add one ingredient so you can isolate if it's food related. Keep adding one item every few days.
Have you tried fermented feed?

It's looonnnggg lol but the main point is probiotics and prebiotics, like the beneficial microbes found in yogurt. Beneficial bacteria help maximize the potential of nutrients found in feed. You can ferment really easy and quick by adding some apple cider vinegar (MUST be whole, including the "mother", not pasteurized) to your feed, with enough water to cover and soak. The microbes in the ACV will colonize much like yeast in bread dough and those microbes are what we are after.

If you have yogurt on hand, that can help in a quick pinch for sour crop as well, but fermenting continuously can prevent any future episodes and increase overall vigor and health of the whole flock.